There was also a serious defence of his brand of One Nation Conservatism and a surprise attack on City fatcats. Here are five things we learned from Boris Johnson's speech:

1 Talk of his demise are premature

The boy is back in town: Boris Johnson may have helped rescue his fortunes in the race to be the next Tory leader (Image: PA)

Those penning their obituaries of Boris Johnson's political career may want to put their pens back in their pockets. Shares in Johnson have been on the slide since the General Election but this was a reminder that he's still a player.

His usual stump speech to Tory conference is 30minutes of unscripted knockabout. This time he delivered a grown up speech lightened with some top-rate jokes.

This speech will have done his leadership prospects no harm and will remind his competitors he is the "Heineken" candidate who can reach audiences other Tories are unable to.

2 The enemies are George Osborne and Theresa May

Piggy in the middle: It is George Osborne and Theresa May who are the main rivals to Boris, not Cameron

We know who the competition is. There was lots of praise for David Cameron whom he lauded for his persistence, calm and patience during the election campaign.

But there is no need to attack the person departing from the stage. Boris focused his artillery on his rivals for the top job: George Osborne and Theresa May.

He accused the Chancellor of stealing the best policies from London's City Hall and took him to task on tax credits (see point 3). His message to Theresa May was more subtle.

A hour after she gave a cynical, bargain-basement speech attacking immigration he offered a defiantly optimistic rallying cry for One Nation Toryism.

This is the ground for the leadership contest: Osborne's ruthless professionalism versus May's hard-core Conservatism versus Boris's splash of sunshine.

This line was particularly powerful: "We must ensure that as we reform welfare and we cut taxes that we protect the hardest working and lowest paid the retail staff, the cleaners, who get up in the small hours or work through the night because they have dreams for what their families can achieve - the people without whom the London economy would simply collapse."

But he also took top bosses to task for paying themselves obscene pay packages while leaving their workers on the minimum wage.

This was a deft demonstration to other Tories on how you stride onto Labour territory.

4 He's still a true-blue Tory

True blue: For all the banter, Johnson is a true-blue Tory (Image: REUTERS)

For all his entertainment value we should never forget that Tory blue blood flows through his veins.

Beneath his call for social unity there was an irreducible Conservative message: a belief that the forces of the market are the best way to drive social change.

His care for the low-paid workers might have carried more weight if he had not put up bus fares.

Nor should we forget he spent a large amount of his speech attacking Labour.

He unfairly conflated the agitators outside the conference with the whole of the Labour Party. The only difference with the other Tory attacks was it was done with more panache.